Bolt-On Cheap Exhaust Option
 

Hi all,

In the never-ending quest to make any bike run better, I was in deep anguish about having that cat in the stock bazooka........but being cheap, I didn't want to spend a fortune. I mean, a 1200.00 Yoshi would have been nice but.....

So, I hunted around and ordered this. It's good for up to a 600cc so I figured, why not? If it doesn't work on the RX3, I'll try it on one of my other rolling stock. It also has a removable baffle for those who like loud.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I started by whacking the stock muffler off as close to the muffler to leave as much flange as possible for mounting the new set-up. I even took a little weld. Finish the end of what is now the mid-pipe off on your grinding wheel and brush. Note the cat. Just a minor obstruction.

I then went by O'Reileys Auto parts and picked up a 1.5"-2" exhaust adapter. They have them stocked. It ran about 3.50. (Pt#548506) After cleaning this up, cut a cross (4 slits) in each end for crimping purposes (pic only shows one end, do both), then paint with your favorite BBQ black paint. Make the slits deep enough for the width of the clamps you'll be using. I prefer T-Bolt clamps. They aren't cheap but by far the best and you can really bear down on them. I still have one more clamp coming for the 2" end, hence the hose clamp for testing purposes. I'll try to mount both springs on the T-Bolt clamp when it gets here. If not, one will suffice. It's a dang snug fit.

The muffler comes with an adapter. Nice piece too. Feel free to whack the 1.5" end off of it....or do what I did and just reverse it and tap it into the muffler. Restriction? Possible....but no where near as restrictive as the cat. I did mark it with a Sharpee in the middle so I could make sure I was seating evenly on both ends of the adapter. Each end is about 1/2" inch+ inserted.

Whack one of the mounting flanges off the stock muffler. You'll need it for mounting the big clamp that goes around the muffler (included). Then measure and drill a hole on the other end of the flange where you'll need it.

Anyway, turned out nice, I thought. I went for a test burn after resetting the ECM and yes, it runs better. A little friskier but I noticed it most at cruise. I didn't need 1/3 throttle to hold cruise speed. Just a crack of throttle did the job. I can't wait to get it back together and do more miles to get the ECM set up properly.

Louder? yes...but not so much it's a problem at all, in my opinion. After all, the stocker isn't that quiet anyway.

So there you have it. A lighter (about 5+ pounds, estimate), attractive, freer flowing, bolt-on muffler for under 100.00....and it has a nice little growl. I'd post a vid if I knew how. ;-) Workin' on my GoPro as we speak.

More pics
 

Here's an end shot so you can see how it looks out the backside. Clears nice, not close to any plastics.
Note: Shameless self-promotion pic of Mrs. 2LZ doing her best Vanna White imitation. The upside is now you can see how the new muffler compares to the stocker.

Bonus!
 

I thought while I had it on the rack, I'd take out the baffle to see how it sounded. Loud. Got it....
In the meantime, for a muffler that's supposed to fit a 600cc bike, the popping on my hand behind the pipe wasn't very much. Once the baffle was out, other than the (removable) block at the end to stop the Rangers coat hanger, there was only 3 sets of three holes (9) to let the exhaust gasses out! WTH!? Cool! It's tune-able! So, instead of 9 holes, I busted out the drill press and doubled it to 18. Much better popping on the hand now and no real noise difference!
Chompin' at the bit now to take her out. Need that clamp so I can put the bags back on.......

Looking good, 2LZ ! Thanks for the link and write-up!

Well done 2LZ .... I'm thinking this is a mod for me :tup: You've really gotta learn how to load vids .. it's idiot proof easy and I'm the poster boy to attest to it!

2lz...Mechanical maestro

Don't get too carried away with video, I can't afford the download stream;)

Remarkably nice clean job, 2LZ. I bet may Zongites will be following in your footsteps on this one. I bet you cut off 5+ pounds there.

Looks nice. Do you think you'll have to rejet?

No jetting on the RX3 in N. America, although a ECU Fuel Mapping will help these engine A LOT from the looks of the roller coaster ride the hp/torque curve shows on the stock bikes ;)

Yes. A remap option would help tremendously on both injector pulse width and swinging the timing advance to a more performance grid....BUT...it has to pass CARB and EPA to start with, so anything like this would have to be done by either CSC or a third party and installed after the fact.
In the meantime, it is a closed loop system running off of an O2 sensor. That O2 sensor will tell the ECM "I need more fuel" when the breathing is opened up "to a point" on the stock mapping.

Follow up Pics
 

Got the bars and bags mounted and back on tonight. As you can see in the first pic (background), I shimmed the bracket out "one 5/16th nut" as it was very close to the bag bar...but not quite touching. I bought some space. Turned out nice. Now you can see what it looks like with the bags....

Performance and Sound
 

Sound: It sounds about the same at idle. Maybe a tad more aggressive.
On the rev, it's got a growl but not too bad at all. Like I said, the stock muffler wasn't quiet when you open the throttle anyway. It does have a nice sound, when on it, more "performance" sounding....but come on folks, it's like trying to make a V6 sound like a V8. No amount of piping will make it sound like it has more CC's. You back off at cruise and it stifles down some. Livable for sure to me.

Power: Non-Scientific seat of the pants "Butt Dyno".
Quicker throttle response in neutral. Snappier.
Actually able to roll it on without dropping a gear under 5k! About 4-4500, just start to roll on the throttle (not spanking it) and it will catch up with itself! That's an improvement. These normally have "zero" under 5k.
After 5-5500k....marked difference. Between 5 grand and redline, definitely more crisp and more pull. Actual acceleration. Not like "DUDE! IT'S GOT A BLOWER!" kind of acceleration....but it's come to life. Not near as much "BUUUHHAAAWWWWW" when you hit it after 5k.

Cruise: Less throttle needed to maintain cruise. More crisp response.

I'm still going to tune with the baffle some more. I think another set of three holes.

That looks very good, 2LZ.

It would be very interesting to see dyno figures. In many cases these mods do not actually produce more hp or torque, in fact it's usually the opposite even with new mapping for the ECU. I saw that on the last two bikes I had on a dyno. They felt like they ran better (and at low rpm the bikes did run smoother) but the hp only changed between 1% and 3%. Fuel mileage suffered quite a bit.

Peter Y.

Thanks Joe....and thanks for the great China trip. I checked in every day. Not sure how you can eat so dang much and still lose weight though ;-)

do you think this would work on a CSC TT250 ????

It may if you can get some pipe bent and correct size adapter.
This one rocks though.....and is very inexpensive for what you receive.

http://www.ebay.com/itm/ALUMINUM-EXH...cAAOSwGvhUICrU

Duh. I thought you put it on the TT. Sorry.

Not a problem. I can see the confusion with how many projects I get going at once. Sometimes I fool myself..... ;-)

Baffle Tuning
 

Ok...so I was thinking today....there's no reason not to get full tuning ability out of this baffle setup. Like with a Super Trapp, you install and remove plates to adjust backpressure for tuning purposes, this little baffle offers much of the same ability but instead of removable plates, you treat it like a recorder (flute type instrument). It has a movable plug. :-)

So, back to the drill press and I drilled as many more rows as I thought necessary to achieve prime objective, plus, every other hole I drilled a tad larger to help with the fine tuning, minus the first three rows. Anal? Oh yah....but fun all the same.

Theoretically, the more back pressure (more holes you block on the flute), the less top end you'll have, while on occasion gaining mid-range or even a little low end in a carburated model. Hopefully the O2 sensor will play.

I took it out after opening the baffle all the way (plug installed in last location opening as many holes as possible) and man....it really opened up the top end (butt dyno). More frisky and crisp, especially between 6 and redline. Drawback? It got a little noisier but not a ton. Just more shrill. Tomorrow, I'll move the plug up to block off two rows of holes and see what that achieves. It SHOULD lose a little of the top end but it will probably quiet it a bit also. We'll see.

This is fun............ "2LZ at Play".

Brilliant! I never thought of moving the plug.


I like your vee block.

Thanks! With the injection, who knows if adjusting the backpressure will work as well as on a carb bike but it's worth a try. I figure the less backed up exhaust gasses (faster scavenging) will lean the O2 sensor to force it to demand more fuel....and visa versa. So far, having all the holes unplugged (full open) has made a noticeable top end difference.

The vee block....Mrs. 2LZ dad cut that out of hardwood for me. It's been a finger saver, for sure. It's my only block of wood I treat as well as a tool. ;-) Oil it twice a year!

I might need to make a block like that. I have two that are made from steel, but I can see uses for wood.


It would be interesting to find out the tolerance of the stock O2 sensor. The next step is a wide band.

I think my next step will be to extend the baffle deeper into the muffler. Lots of room in there. If I can get a tube that will just slip over the end of the stock baffle and extend it another couple/3 inches, that will give it freer breathing, plus more obstacles for the sound waves to hit. I can then move the plug to the end. I've been plotting on a pointy or bullet shaped plug to help move the exhaust charge around the baffle better and not hit such a brick wall. Just depends on what I can find in my stash....

This stupid baffle has become just too much fun. ;-)

I'm with you on the bullet shape. My old Gio quad had that in the stock muffler, which I cannibalized for my XL250S project a few years ago. In that case, I measured the area of the exhaust inlet and calculated how many 1/4" holes would be needed to equal the total area (I then drilled a couple more for good measure). I was quite pleased with the results, since the original Honda exhaust had gone to its reward several years earlier.

A question for CSCdude, if i want to do this to my bike, will it void my 2 yr warranty?

Update:
 

I've been messing with the baffle more. As pictured above, I ran the row of holes to the end, on all three rows. I played with the spark block moving it into different spots. The best it ran, with the best throttle response was obviously in the last location, with the most holes exposed.

So yesterday, I decided to drill 3 more holes each, between the rows of holes, adding some intermediate exit holes. (9 total)
I'm not sure if it changed the running personality....but it sure made it louder to the rider.

Odd thing was, Mrs. 2LZ was behind me on the TT and neighbor Ron was also back there on Q...and both said the RX3 was very quiet to them. Ron said the TT was louder with the new pipe. Boy, you couldn't have told me that from where I was sitting. Mrs. 2LZ rode the RX3 later in the day and said that it is loud in the riders seat. I was on the TT and it sounded nice and quiet when I was behind it. Weird.

The muffler exits about the same place the stock one did. I'm thinking of moving it back further past the bag to see if I can move some of that noise away. Other than that, so far, happy.

Are you sure the noise you're hearing as rider is not from the intake?

That's a possibility but it's not a sucking sound, definitely has the pop and rhythm of the exhaust note. I'm wondering if it's echoing more because of the sound being trapped between the empty bag (like a drum) and the bike. I'm going to remove the bag and see if it changes.
I did move the spark block last night up one row to cover 9 holes and it seemed to cut the shrill note. It's not that it's too loud, per se...but it's the new tone after the additional holes that kind of sharp to the ear.

Sound from the muffler should be directed BACK and AWAY from the rider... something isn't right from the sounds of things :hehe:

I'm wondering if the new muffler has a 'complete and proper seal' around the 'muffler / mid-pipe section'... it could explain why the noise is louder for the rider and not those behind you, might be letting exhaust/sound waves out and back towards the rider if the muffler has any kind of gap around it and the exhaust pipe

?? Just a thought from someone a thousand + miles away, maybe start the bike and use your hand around the muffler and other exhaust parts to check for any air leaks ??

Good thoughts!....but I double checked the joints last night and they're tight. That in mind, the stock muffler produced quite a bit of sound for the rider, especially when you were on the throttle. If you look at how the RX3 system is set up, the muffler doesn't even exit the entire rear end of the bike, as seen in the attached pic. The muffler doesn't even clear the bag and the exhaust exit is trapped behind it. I think my louder pipe may enhance this effect. Just a guess though.

Litmus test possibly coming up this Sunday. My brother is bringing up his bone-stock RX3. He has yet to even wash off the original Oregon dirt.

I'm curious to see if there's any real difference in rideability between the two with the new muffler or not. I've gotten so used to how mine is now, it should be interesting to compare.

Ive been wondering if it could be sound bouncing off that case? :hmm:

As compared to many bikes I've had, the RX3 exhaust exit isn't very far behind the riders head, then add being trapped between the bike and the bag. I think this could contribute to the stock exhaust being kind of noisy on acceleration.

It's not like it's too noisy right now. I moved the spark block up one hole last night and it toned it down enough. I'm just in 'experimentation mode' more than anything at the moment. Must work on something!

Hi 2LZ,

Thanks for the detailed write up on this! Is there any chance you could share some additional info about the purchase of your pipe? The amazon link is busted, and I've done a fair amount of searching for the same one or similar, but haven't definitely found it yet. I'd be happy with just dropping 5 lbs and getting a smaller profile, any performance/sound benefits are just bonus in my eyes.

Oh, and on the later topic of the RX3 being extra noisy due to the pannier box, I replaced my boxes with removable soft bags last year and haven't noticed a difference even with the bags off. However I think there may have been a little less vibration noise coming from the hollow empty boxes.

Hi RC and thank you for your interest. Here's a link to the same basic muffler that I just mounted on my Qlink. There's a number of this type of muffler available on Amazon last I checked.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I can't say, even after drilling out the baffle, that there's any nopticable performance difference. I THINK I have a little more grunt under 5k rpms. I've got great results changing exhaust on all my CB's, but not the RX3. I feel it has to do with injector and ECU mapping.

The sound is a little louder but nothing out of the ordinary.
Truth be told, I'm going to run my RX3 against my wife's RX3 and if there's no real difference, I'll probably end up acquiring a stock exhaust somewhere. We'll see......

Member rtking acquired great results, dyno proven, on his RX3. He had a muffler shop make a mid pipe for his Akrapovic muffler. Plus, he's done some additional gearing and breather work, I believe.

Long overdue update:

It's official. After a number of miles and months, I've found, at least on my RX3, that changing the exhaust to a more free flowing unit and eliminating the cat, makes no noticeable difference in performance. I think I may imagine a tad more under 5 grand but it's most likely my wishful thinking. No, there was no dyno involved, so if there's an improvement in numbers, I can't tell. I even pulled the baffle and ran an Uni filter at one point but it basically ran the same.....just far louder.

The Mrs. and I took out both RX3's over the holiday weekend. Hers is bone stock, mine has the free flow muffler. We ran them next to each other, WFO up the same steep hills, holeshots on flat ground from a stop and roll ons from 40 mph. The bikes were all but glued to each other (both have the same gearing).

My uneducated guess would be that the mapping of the EFI and spark advance really put limitations on what mods may accomplish. I don't think any mod will make much difference until we can achieve a reflash of some sort. Again, just a guess. I used to be a mechanic, but I don't even play one on TV anymore.

As stated prior, this was the experience with my bikes. Your results may vary. I'm thinking a stock pipe is in my future to quiet it back down.

why would you do that? don't you know that loud pipes save lives? :p

That's good info 2LZ. I guess the only reason to change out the exhaust is for weight then.

The Haunting Solution
 

The secret is in the dna (the mapping)

Max Output:32 hp @ 8000rpm

http://www.pitsterpro.com/bike/specs/id/66

:hmm: